The concentration of vasopressin (ADH) in blood is the resultant of the release of the hormone into the blood from the neurohypophysis and the removal of the hormone from the blood, primarily by the liver and kidneys. The objective of this proposal is to study the factors involved in the physiological control of these two determinants of the plasma concentration of ADH. The specific experiments which have been proposed deal with the following: role of the renin-angiotensin system in the control of ADH release; role of the prostaglandins in the control of ADH release; role of the kidneys in the metabolism of ADH.